JP7328461B2 - Method and apparatus for inter-system mobility support in wireless communication system - Google Patents

Description

The present invention relates to a method and apparatus for providing service in a wireless communication system, and more particularly to a method and apparatus for providing inter-system mobility assistance in a wireless communication system.

^Efforts to develop an improved 5th generation (5G) communication system or pre-5G communication system to meet the increasing demand for wireless data traffic after the commercialization of 4G ( ^4th generation) communication systems is done. For such reasons, the 5G communication system or pre-5G communication system is called a communication system beyond 4G network or a system after LTE (Long Term Evolution) (post LTE).

To achieve high data transmission rates, 5G communication systems are being considered for implementation in the ultra-high frequency (mmWave) band (eg, 60 Giga (60 GHz) band). In order to mitigate the radio wave path loss in the ultra-high frequency band and extend the radio wave transmission distance, the 5G communication system uses beamforming, massive MIMO (multi input multi output), all Technologies of full dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large scale antennas are being discussed.

In addition, in order to improve the network of the system, the 5G communication system includes advanced small cells, advanced small cells, cloud RAN (radio access network), ultra-high density networks. (ultra-dense network), device to device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (coordinated mult i-points), and Techniques such as receive interference cancellation are being developed.

In addition, the 5G system includes FQAM (Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation), which is an advanced coding modulation (ACM) method, and SWSC (Sliding Window Superpo). site coding), as well as advanced connection technology Some FBMC (Filter Bank Multi Carrier), NOMA (Non Orthogonal Multiple Access), and SCMA (Sparse Codem Multiple Access) have been developed.

With the development of various information technology (IT) technologies, network equipment has evolved into a virtualized network function (NF) by applying virtualization technology. , the virtualized NF is implemented in a software form without physical restrictions, and is installed/operated from various types of clouds and data centers (DC: data center). In particular, NFs are freely scaled or initiated or terminated according to service requirements, system capacity and network load.

In order to support various services in such various network structures, network slicing technology has been introduced. Network slicing is a technique of logically composing a network with a collection of network elements (NFs) for supporting specific services and isolating them from other slices. One terminal can be connected to two or more slices when receiving various services.

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus and method for effectively providing services in a wireless communication system.

A method for supporting inter-system mobility of a first entity according to an aspect of the present invention to achieve the above object includes: APN (access point name) information for a terminal to request packet data network (PDN) connection; receiving a session creation request message including fields indicating capability information on subscriber identification information of the terminal and slice identification information of the terminal; system), and based on the determination result, sending a request for subscriber information including the subscriber identification information and the APN information to a second entity. receiving from the second entity a response to the request for subscriber information including identification information of one or more subscribed network slices corresponding to the subscriber identification information; and identification of the one or more subscribed network slices. and providing at least one of the information to the terminal.

The capability information related to slice identification information of the terminal includes information indicating whether the terminal is capable of receiving identification information of two or more network slices, and includes identification information of the one or more subscribed network slices. providing to the terminal at least one of the identification information of one or more network slices among the identification information of the one or more subscribed network slices based on a field indicating capability information about the slice identification information of the terminal to the terminal.
At least one of identification information of the one or more subscribed network slices provided to the terminal may be included in a predetermined field within a create session response message.
The method comprises: transmitting a message requesting selection of a network slice to a third entity based on identification information of the one or more subscribed network slices; receiving a response message containing one or more slice identities selected by the third entity, providing at least one of the identities of the one or more subscribed network slices to the terminal. The step of providing may include transmitting at least one of the selected one or more slice identification information to the terminal.
if the response to the request for subscriber information includes identification information of two or more network slices, the response to the request for subscriber information includes information for determining a default network slice; It may contain information about priorities among network slice identities.
At least one of the identities of the one or more subscribed network slices provided to the terminal may be used when the terminal moves to 5GS.
The first entity is a combo node of PGW-C (PDN gateway control) of EPS (Evolved Packet System) and SMF (Session Management Function) of 5GS, and the second entity is UDM (Unified Data Management), The third entity may be one of HSS (Home Subscriber Server) and UDR (Unified Data Repository), and the third entity may be NSSF (Network Slice Selection Function).

A communication method for a terminal provided with identification information of a network slice according to one aspect of the present invention to achieve the above object is a PDN including information on a predetermined APN (access point name) in a MME (Mobility Management Entity). (Packet Data Network) transmitting a connection request message; receiving, in response to the PDN connection request message, a response message including at least one network slice information corresponding to the APN; and storing at least one network slice information of , wherein the at least one network slice information is used when the terminal moves to 5GS (5G system).

A first entity supporting inter-system mobility according to an aspect of the present invention to achieve the above object includes: a transceiver; APN (access point name) information for a terminal to request PDN connection; receiving a session creation request message including a field indicating capability information about the user identification information and the slice identification information of the terminal, and based on the session creation request message, movement to 5GS (5G system) for the PDN connection is performed. determining whether it is necessary, transmitting a request for subscriber information including the subscriber identification information and the APN information to a second entity based on the determination result, and sending the subscriber identification from the second entity; receiving a response to the request for subscriber information including identification information of one or more subscribed network slices corresponding to the information, and providing at least one of the identification information of the one or more subscribed network slices to the terminal; a processor coupled to the transceiver configured to:

The capability information regarding the slice identification information of the terminal includes information indicating whether the terminal is capable of receiving identification information of two or more network slices, and the processor controls the capability information regarding the slice identification information of the terminal. to provide the identification information of one or more network slices among the identification information of the one or more subscribed network slices to the terminal, based on the field indicating the .
At least one of identification information of the one or more subscribed network slices provided to the terminal may be included in a predetermined field within a create session response message.
The processor transmits a message requesting selection of a network slice to a third entity based on the identification information of the one or more subscribed network slices, and the third entity among the identification information of the one or more subscribed network slices. receiving a response message including one or more slice identities selected by three entities, and transmitting at least one of the selected one or more slice identities to the terminal.
if the response to the request for subscriber information includes identification information of two or more network slices, the response to the request for subscriber information includes information for determining a default network slice; It may contain information about priorities among network slice identities.
The first entity is a combo node of PGW-C (PDN gateway control) of EPS (Evolved Packet System) and SMF (Session Management Function) of 5GS, and the second entity is UDM (Unified Data Management), It may be one of HSS (Home Subscriber Server) and UDR (Unified Data Repository), and the third entity may be NSSF (Network Slice Selection Function).

A terminal provided with identification information of a network slice according to one aspect of the present invention made to achieve the above object includes a transceiver and a PDN including information on a predetermined APN (Access Point Name) in an MME (Mobility Management Entity) (Packet Data Network) transmitting a connection request message; receiving a response message including at least one network slice information corresponding to the APN as a response to the PDN connection request message; a processor coupled to the transceiver configured to store network slice information, wherein the at least one network slice information is utilized when the terminal moves to 5GS (5G system).

According to the present invention, it is possible to provide an apparatus and method for effectively providing services in a wireless communication system.

1 illustrates a wireless communication system according to an embodiment of the invention; FIG. FIG. 4 illustrates an interworking structure of 5GS and EPS in non-roaming situation according to an embodiment of the present invention; FIG. 4 illustrates a method of transmitting NW slice information in a 5G-4G interworking environment according to an embodiment of the present invention; FIG. 4 illustrates a method of transmitting NW slice information in a 5G-4G interworking environment according to an embodiment of the present invention; FIG. 4 illustrates a method of transmitting NW slice information in a 5G-4G interworking environment according to an embodiment of the present invention; 4 is a flow chart of a terminal communication method according to an embodiment of the present invention; 3 is a flow chart of a communication method of a PGW (PDN (packet data network) gateway) according to an embodiment of the present invention; 1 is a block diagram showing the configuration of a terminal according to one embodiment of the present invention; FIG. Figure 3 is a block diagram illustrating an NF configuration according to one embodiment of the invention;

Hereinafter, specific examples of embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, in the description of the present embodiment, if it is determined that a specific description of related known functions or configurations unnecessarily obscure the gist of the present invention, the detailed description will be omitted. The terms described below are terms defined in consideration of the functions of the present invention, and they differ depending on the user's or operator's intentions or customs. Therefore, the definition should be based on the content throughout this specification.

Advantages and features of the invention, as well as the manner in which they are achieved, will become apparent with reference to the embodiments described in detail below in conjunction with the drawings. The present invention, however, should not be limited to the embodiments disclosed below, but may be embodied in different and varied forms, and merely this embodiment shall provide a complete and complete disclosure of the invention and the art to which the invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

It will be understood that each block of the process flowcharts, and combinations thereof, may be implemented by computer program instructions. Those computer program instructions may reside in a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus and thus may be executed through the processor of the computer or other programmable data processing apparatus. Instructions create the means to perform the functions described in the flow chart blocks. These computer program instructions are computer-usable or stored in computer-readable memory directed to a computer or other programmable data processing apparatus to perform functions in a particular manner, and therefore are The instructions stored in the computer usable or computer readable memory can produce an item of manufacture containing instruction means for performing the functions described in the flowchart blocks. Computer program instructions are embodied on a computer or other programmable data processing device such that a series of operational steps are performed on the computer or other programmable data processing device to perform a computer executed process. to perform on a computer or other programmable data processing device provide steps for performing the functions described in the flowchart blocks.

Also, each block represents a module, segment, or portion of code containing one or more executable instructions for performing the specified logical function. It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order. For example, two blocks shown in succession may in fact be performed substantially concurrently, or the blocks may sometimes be performed in reverse order by the functionality.

Here, the term "-part" used in the present embodiment means a hardware component such as software, FPGA (Field Programmable Gate Array), or ASIC (Application Specific Integrated Circuit). ' fulfills a role. However, "-part" is not meant to be limited to software or hardware. A "part" is configured to reside on an addressable recording medium and configured to be played back by one or more processors. Thus, by way of example, "part" refers to components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, Includes drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided from among the components and "sections" may be combined into fewer components and "sections" or further separated into additional components and "sections". Not only that, but the components and "parts" are embodied to play one or more CPUs in the device or in the security multimedia card. Also, in embodiments, "a unit" includes one or more processors.

The terminology used in the present invention is for the purpose of describing particular embodiments only and is not intended to limit the scope of other embodiments. Singular expressions include plural expressions unless the context clearly dictates otherwise. Terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the arts described herein. In the terms used herein, common pre-defined terms shall be construed with the same or similar meanings as they have in the context of the relevant art and are not expressly defined herein. It should not be construed in any sense that is ideal or overly formal. Any term defined herein, as the case may be, is not to be construed as excluding any embodiment of the present invention.

A hardware approach will be exemplified and described as various embodiments of the present invention described below. However, since various embodiments of the present invention include techniques using both hardware and software, various embodiments of the present invention do not exclude software-based approaches.

TECHNICAL FIELD The present invention relates to a method and apparatus for supporting various services in a wireless communication system. Specifically, the present invention describes techniques for supporting various services by supporting mobility of terminals in a wireless communication system.

Terms used in the following description to identify connection nodes, terms that refer to network entities or NFs (network functions), terms that refer to messages, terms that refer to interfaces between network objects, and various other terms. Terms that refer to such identification information are exemplified for convenience of explanation. Accordingly, the invention is not intended to be limited to the terms hereinafter described, and other terms may be used to refer to subjects having equivalent technical meanings. For example, in the embodiment of the present invention, the function of one NF, NSSF (network slice selection function), is performed by another NF, NRF (network repository function).

In the following, for convenience of description, this specification uses terms and names defined in 3GPP® LTE (3rd generation partnership project long term evolution) and 5G standards. However, the present invention is not limited by the terms and names described above and applies equally to systems according to other standards. In particular, the invention applies to 3GPP® NR (new radio) (5th generation mobile communication standard). Herein, eNB is used mixed with gNB for convenience of explanation. That is, the base station described with eNB indicates gNB. Alternatively, the base station described in gNB indicates eNB. Alternatively, the node described in the base station indicates eNB or gNB. Also, the term terminal refers not only to mobile phones, NB-IoT devices and sensors, but also to other wireless communication devices.

Hereinafter, a base station is an entity that performs resource allocation for a terminal, and is at least one of a gNodeB, an eNodeB, a NodeB, a BS (base station), a radio access unit, a base station controller, or a node on a network. be. A terminal includes a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system that performs communication functions. It goes without saying that the above examples are not restrictive.

FIG. 1 illustrates a wireless communication system according to one embodiment of the invention.

Referring to FIG. 1, a radio access node (RAN) 110 and a user equipment (UE) 120 are illustrated as part of nodes that utilize radio channels in a wireless communication system. Although FIG. 1 illustrates only one base station 110 and one terminal 120, other base stations identical or similar to base station 110 are also included. Also, FIG. 1 illustrates a case where only one terminal 120 communicates within one base station 110 . However, it is obvious that multiple terminals can actually communicate within one base station 110 .

According to one embodiment of the invention, base station 110 is a network infrastructure that provides wireless connectivity for terminals 120 . A base station 110 has coverage defined as a certain geographical area based on the distance over which it can transmit a signal. In addition to the base station, the base station 110 includes an 'access point (AP)', an 'eNB (eNodeB)', a '5G node (5th generation node)', a 'wireless point', Also referred to as a "transmission/reception point" (TRP) or other term with equivalent technical meaning. It goes without saying that the invention is not limited to the above examples.

According to one embodiment of the present invention, terminal 120 is a device used by a user to communicate with base station 110 over a wireless channel. In some cases, terminal 120 is operated without user involvement. For example, terminal 120 is a device that performs machine type communication (MTC) and is not carried by a user, but terminal 120 illustrated in FIG. 1 includes at least one user-carried device. , including at least one MTC. The terminal 120 in FIG. 1 is also referred to as a "terminal," "mobile station," "subscriber station," "remote terminal," and "wireless terminal." , “user device”, or other terms with equivalent technical meanings.

According to one embodiment of the invention, AMF 131 is a network entity that manages wireless network access and mobility management for terminal 120 . SMF 132 is a network entity that manages the connection of packet data networks for providing packet data to terminal 120 . A connection between the terminal 120 and the SMF 132 is a PDU (packet data unit) session.

According to one embodiment of the present invention, user plane function (UPF) 133 is a gateway or network entity acting as a gateway that communicates packets sent and received by terminal 120 . The UPF 133 is connected to a data network (DN) 140 connected to the Internet and provides a path for data transmission/reception between the terminal 120 and the DN 140 . Therefore, the UPF 133 routes data to be transmitted to the Internet among packets transmitted by the terminal 120 to the Internet data network.

According to one embodiment of the invention, a network slice selection function (NSSF) 134 is a network entity that performs the network selection operations described herein, eg, selecting a network slice. The operation of the NSSF device 134 is described in more detail in the figures below.

According to one embodiment of the present invention, an AUSF (authentication server function) device 151 is a network entity that provides services for subscriber authentication processing.

According to one embodiment of the present invention, the network exposure function (NEF) 152 has access to information managing the terminal 120 in the 5G network, subscription to mobility management events of the terminal, A network entity that subscribes to session management events of a terminal, requests session-related information, sets charging information of the terminal, requests PDU session policy changes to the terminal, and transmits small data about the terminal. be.

According to one embodiment of the present invention, NRF (Network Repository Function) 153 is a NF (Network Entity) having a function of storing state information of NFs and processing requests for other NFs to search for connectable NFs. is.

According to one embodiment of the present invention, PCF (Policy and Charging Function) 154 is a network entity that applies the mobile operator's service policy, charging policy, and PDU session policy for terminal 120 .

According to one embodiment of the invention, Unified Data Management (UDM) 155 is a network entity that stores information about subscribers and/or terminals 120 .

According to one embodiment of the present invention, AF (Application Function) 156 is a NF (Network Entity) having the function of interfacing with a mobile communication network to provide services to users.

According to one embodiment of the present invention, SCP (Service Communication Proxy) 157 is a NF (Network Entity) that provides functions such as NF discovery and inter-NF messaging for communication between NFs. The SCP 157 operates in a form integrated with the NRF 153 according to operator selection, in which case the SCP 157 includes the functions of the NRF (Network Repository Function) 153, or conversely the NRF 153 includes the functions of the SCP 157.

In the following, for convenience of explanation, NFs will be used as a generic term for information exchange targets for connection control and state management. The NF includes at least one of, for example, an Access and Mobility Management Function (AMF) device, a Session Management Function (SMF) device, a Network Slices Selection Function (NSSF) device. is one. However, embodiments of the present invention actually apply equally when NFs are embodied by instances (AMF instance, SMF instance, NSSF instance, etc., respectively). Also, according to one embodiment of the present invention, NFs are called entities.

On the other hand, in the present invention, NFs are merged with each other, or one NF includes functions of other NFs. For example, NRF includes the functionality of NSSF. Also, in disclosing embodiments of the present invention, specific operations are described with reference to one NF, but the subject matter of the invention applies to other NFs including and operating the functionality.

In the present invention, an instance means that a specific NF is embodied in a software code form. An instance is a given NF by being allocated physical or/and logical resources from the computer system to perform the function of the NF in a specific computer system that exists on a physical computer system, for example, a core network. perform the functions of Therefore, AMF instances, SMF instances, and NSSF instances are used by being allocated physical and/or logical resources for AMF, SMF, and NSSF operations from specific computer systems existing on the core network, respectively. As a result, physical and/or logical resources for AMF, SMF, and NSSF operations are allocated from specific computer systems residing on the core network when physical AMF, SMF, and NSSF devices are present. The AMF instance, the SMF instance, and the NSSF instance used in the same operations perform the same operations.

As a result, physical and/or logical resources for AMF, SMF, and NSSF operations are allocated from specific computer systems residing on the core network when physical AMF, SMF, and NSSF devices are present. The AMF instance, the SMF instance, and the NSSF instance used in the same operations perform the same operations. Therefore, in the embodiments of the present invention, items described as NF (AMF, SMF, UPF, NSSF, NRF, SCP, etc.) are replaced with NF instances, or conversely, items described as NF instances are replaced with NF instances. applied instead of Similarly, in the embodiments of the present invention, items described as network slices (NW slices) are replaced with NW slice instances, or conversely, items described as NW slice instances are replaced with NW slices. be done. Also, in the embodiments of the present invention, the terms "subscriber" and "terminal" are used interchangeably.

FIG. 2 illustrates an interworking structure between a 5G system (5GS) and an evolved packet system (EPS) in a non-roaming situation according to an embodiment of the present invention.

5GS is configured by NR (new radio) base station 150, AMF 145, SMF 120, UPF 125, PCF 115, and UDM 110. The EPS is composed of E-UTRA base station 140, MME 135, SGW 130, PGW-U 125, PGW-C 120, PCRF 115 and HSS 110. It goes without saying that the EPS may consist of fewer or more entities than in FIG.

According to one embodiment of the present invention, the 5GS UDM 110 and the EPS HSS 110 are configured in one combo node. The 5GS SMF 120 and the EPS PGW-C 120 consist of one combo node. Also, according to an embodiment of the present invention, the UDM+HSS 110 node stores subscriber information of terminals. The 5GS UPF 125 and the EPS PGW-U 125 consist of one combo node. Terminal 155 connects to EPS MME 135 via E-UTRA base station 140 and utilizes EPS network services. It goes without saying that the above examples are not restrictive.

Also, the terminal 155 connects to the 5GS AMF 145 via the NR base station 150 and uses the 5GS network service. Although FIG. 2 shows the interworking structure for non-roaming situations, other embodiments of the present invention are not only applicable to non-roaming situations, but also for roaming situations (local breakout or home-routed). Applies.

If a 5G-supported terminal can selectively connect to 5GS and EPS, depending on network conditions, the terminal may first connect to 5GS and then move to EPS (5GS to EPS interworking), or vice versa to EPS first. After connecting, move to 5GS (EPS to 5GS interworking). When the terminal first connects to EPS and then moves to 5GS, the PDN connection generated in EPS is converted to a 5GS PDU session, and the terminal transmits NW (network) slice information ( NW slice identifier) must be entered. In EPS, the network cannot be configured or selected in NW slices, so in order to support the mobility of such terminals to 5GS, the NW slice identifier to be used in 5GS from now on when connecting to EPS is pre-configured. You need a way to communicate.

Depending on the configuration of the 5GS network, two or more DNN (data network name) (a concept equivalent to or similar to APN (access point name)) is mapped to one NW slice, or conversely, one DNN is supported with two or more NW slices. In that case, if the NW slice identifier delivered from the EPS to the terminal does not match the NW slice identifier used in the 5GS network or the mapping with the DNN is configured differently, when the terminal moves from the EPS to the 5GS In some cases, conversion to a PDU session may fail or service continuity may not be guaranteed. Therefore, there is a need for a method to solve the above problems.

FIG. 3 illustrates a method for transmitting NW slice information in a 5G-4G interworking environment according to an embodiment of the present invention.

In step 301, a process for establishing a PDN connection with EPS (eg, 4G network) is performed at the request of the terminal. Step 301 is merged with the attach requested by the terminal. In step 301, the terminal includes an APN for which a PDN connection is to be established in a request message.

According to an embodiment of the present invention, the request transmitted by the terminal includes information indicating whether it can receive two or more S-NSSAIs through PCO (Protocol Configuration Option) or ePCO (extended PCO). is included. It is indicated in the capability of the NAS message transmitted by the terminal or in a separate indicator, or included in a part of the PCO (protocol options, etc.). Here, it goes without saying that there is no limitation to the method of conveying information indicating whether or not two or more S-NSSAIs can be received, without being limited to the above examples.

According to an embodiment of the present invention, a NAS-level PDN connection establishment request message transmitted by a terminal is delivered to a mobility management entity (MME) through a base station, and the MME establishes a PDN connection according to the terminal's request and subscription information. Select SGW (serving GW) and PGW (PDN GW) to be used. The MME transmits a request message (Create Session Request) for creating a session to the SGW. identity), APN, and PCO. The SGW transmits a request message (Create Session Request) for creating a session to the PGW-C, and the message for creating a session includes a UE/subscriber identity (IMSI) for PDN connection, APN and PCO are included.

In step 302, PGW-C (PDN gateway control plane) supports interworking with 5GS and includes the function of SMF. Here, it goes without saying that a PGW that is not PGW-C (or a combo node of PGW-C and PGW-U) can perform it. PGW-C, if the session creation request received in step 301 is intended for 5GS interworking (which is determined based on the local settings of PGW-C and the information received via MME, SGW), A request to receive 5GS NW slice information for the subscriber and the requested APN is sent to the NF that stored the subscriber information. NF is one of UDM, HSS, and UDR, and the service requested by PGW-C is a Slice Selection Subscription Data Retrieval request. The Slice Selection Subscription Data Retrieval request includes the subject subscriber's identifier (SUPI) (using the subscriber ID received in step 301) and additionally carries with it the APN for the current session.

In step 303, the NF that has stored the subscriber information delivers slice information about the subscriber as a response to the PGW-C's request. NF is one of UDM, HSS, and UDR, and the responding service is Slice Selection Subscription Data Retrieval response. The response message contains the subscribed NSSAI (one or more subscribed S-NSSAIs) for the subscriber.

In step 304, the PGW-C selects the identifier of the NW slice (ie, S-NSSAI) to inform the terminal using the NSSAI received in the response message. If the NSSAI of the response message contains only the S-NSSAI of 1, it is notified to the terminal. If the NSSAI of the response message contains more than one S-NSSAI, both of them are notified to the terminal.

If the PGW-C supports only some of the S-NSSAIs included in the NSSAI of the response message, the PGW-C only informs the terminal of the S-NSSAIs it supports. If only some of the S_NSSAIs included in the NSSAI of the response message can work with the current target APN, only the APN and the mapped S-NSSAI are notified to the terminal. The S-NSSAI notified to the terminal uses PCO (Protocol Configuration Option) or ePCO. That is, the PGW-C generates a PCO containing at least one S-NSSAI to inform the terminal. If the S-NSSAI that can be notified to the terminal is 2 or more, considering whether the corresponding function of the terminal received in step 1 is supported, if 2 or more S-NSSAI cannot be received, Only one S-NSSAI is selected for transmission.

At step 305, the PCO is conveyed in the Create Session Response message in response to the SGW and MME.

In step 306, the MME includes a PCO including slice information (one or more S-NSSAIs) received from the PGW-C and SGW in the NAS response message to be transmitted to the terminal.

In step 307, the terminal stores the NSSAI received from the MME as information (context) of the PDN connection. The stored NSSAI is used when the UE determines the Requested NSSAI in the registration process when moving to 5GS, or when the PDN connection should be moved to 5GS.

According to an embodiment of the present invention, the NSSAI included in the Registration Request message transmitted by the terminal after moving to 5GS is the union of the NSSAIs received for all generated PDN connections. If two or more S-NSSAIs are stored for the corresponding PDN connection, the terminal applies a method of selecting an S-NSSAI when creating a PDU session in 5GS and sends it to 5GS in a PDU session request message. Transmit including the preserved S-NSSAI. In addition, according to an embodiment of the present invention, only the S-NSSAI that overlaps the S-NSSAI saved for the PDN connection in the Allowed NSSAI included in the Registration Accept message received from the AMF when moving to 5GS. It is included in the PDU session request message and transmitted.

FIG. 4 illustrates a method for transmitting NW slice information in a 5G-4G interworking environment according to an embodiment of the present invention.

In step 401, a process for establishing a PDN connection with an EPS (eg, 4G network) is performed at the request of the terminal. Step 401 is merged with attach requested by the terminal. In step 401, the terminal includes an APN for which a PDN connection is to be established in a request message.

According to an embodiment of the present invention, the request transmitted by the terminal includes information indicating whether it can receive two or more S-NSSAIs through Protocol Configuration Option (PCO) or ePCO. It is indicated in the capability of the NAS message transmitted by the terminal or in a separate indicator, or included in a part of the PCO (protocol options, etc.). Here, it goes without saying that there is no limitation to the method of conveying information indicating whether or not two or more S-NSSAIs can be received, without being limited to the above examples.

According to an embodiment of the present invention, a NAS-level PDN connection establishment request message transmitted by a terminal is delivered to an MME through a base station, and the MME selects an SGW and a PGW for establishing a PDN connection according to the terminal's request and subscription information. select. The MME transmits a request message (Create Session Request) for creating a session to the SGW. and PCO. The SGW transmits a request message (Create Session Request) for creating a session to the PGW-C, and the message for creating a session includes a UE/subscriber identity (IMSI) for PDN connection, APN and PCO are included.

At step 402, the PGW-C supports interworking with 5GS and includes the functionality of SMF. PGW-C, if the session creation request received in step 401 is intended for 5GS interworking (which is determined based on the local configuration of PGW-C and the information received via MME, SGW), A request to receive 5GS NW slice information for the subscriber and the requested APN is sent to the NF that stored the subscriber information. NF is one of UDM, HSS, and UDR, and the service requested by PGW-C is a Slice Selection Subscription Data Retrieval request. The Slice Selection Subscription Data Retrieval request includes the target subscriber identifier (SUPI) (using the subscriber ID received in step 401) and additionally carries with it the APN for the current session.

In step 403, the NF that has stored the subscriber information delivers slice information about the subscriber as a response to the PGW-C's request. NF is one of UDM, HSS, and UDR, and the responding service is Slice Selection Subscription Data Retrieval response. The response message contains the subscribed NSSAI (one or more subscribed S-NSSAIs) for the subscriber.

If the subscribed NSSAI for a subscriber includes two or more S-NSSAIs, the NF additionally includes information for determining the default S-NSSAI for that subscriber in the response message. If an APN is included in the request received in step 402, it also includes information used to determine the S-NSSAI to apply as the default for that APN. Alternatively, the NF determines the priority of the subscribed S-NSSAIs to the subscriber, configures information to determine the priority for each S-NSSAI, and responds to the response message. Priority either explicitly signals the priority value for each S-NSSAI or includes a list ordered by priority in the response message. It goes without saying that the above examples are not restrictive.

In step 404, the PGW-C selects the identifier of the NW slice (ie, S-NSSAI) to inform the terminal using the NSSAI received in the response message. If the NSSAI of the response message contains only the S-NSSAI of 1, it is notified to the terminal. If the NSSAI in the response message contains more than one S-NSSAI and the response specifies the default S-NSSAI, PGW-C will select it preferentially. Or, if the NSSAI of the response message contains two or more S-NSSAIs, and the priority among the S-NSSAIs is determined through the response, the PGW-C preferentially selects the S-NSSAI with the highest priority. . The PGW-C notifies the terminal of one selected S-NSSAI, and the S-NSSAI notified to the terminal uses PCO (Protocol Configuration Option) or ePCO. That is, the PGW-C generates a PCO containing at least one S-NSSAI to inform the terminal. If the S-NSSAI that can be notified to the terminal is 2 or more, considering whether the corresponding function support of the terminal received in step 401 is performed, if 2 or more S-NSSAI cannot be received, Only one S-NSSAI is selected for transmission.

At step 405, the PCO is conveyed in the Create Session Response message in response to the SGW and MME.

In step 406, the MME includes the PCO including the slice information (one or more S-NSSAIs) received from the PGW-C and SGW in the NAS response message to be transmitted to the terminal.

In step 407, the terminal stores the NSSAI received from the MME as information (context) of the PDN connection. The stored NSSAI is used when the UE determines the Requested NSSAI in the registration process when moving to 5GS, or when the PDN connection should be moved to 5GS.

According to an embodiment of the present invention, the NSSAI included in the Registration Request message transmitted by the terminal after moving to 5GS is the union of the NSSAIs received for all generated PDN connections. If two or more S-NSSAIs are stored for the corresponding PDN connection, the terminal applies a method of selecting an S-NSSAI when creating a PDU session in 5GS and sends it to 5GS in a PDU session request message. Transmit including the preserved S-NSSAI. In addition, according to an embodiment of the present invention, only the S-NSSAI that overlaps the S-NSSAI saved for the PDN connection in the Allowed NSSAI included in the Registration Accept message received from the AMF when moving to 5GS. It is included in the PDU session request message and transmitted.

FIG. 5 illustrates a method for transmitting NW slice information in a 5G-4G interworking environment according to an embodiment of the present invention.

In step 501, a process for establishing a PDN connection with EPS (eg, 4G network) is performed at the request of the terminal. Step 501 is merged with attach requested by the terminal. In step 501, the terminal includes an APN for which a PDN connection is to be established in a request message.

According to an embodiment of the present invention, the request transmitted by the terminal includes information indicating whether it can receive two or more S-NSSAIs through PCO (protocol configuration option) or ePCO. It is indicated in the capability of the NAS message transmitted by the terminal or in a separate indicator, or included in a part of the PCO (protocol options, etc.). Here, it goes without saying that there is no limitation to the method of conveying information indicating whether or not two or more S-NSSAIs can be received, without being limited to the above examples.

According to an embodiment of the present invention, a NAS-level PDN connection establishment request message transmitted by a terminal is delivered to an MME through a base station, and the MME selects an SGW and a PGW for establishing a PDN connection according to the terminal's request and subscription information. select. The MME transmits a request message (Create Session Request) for creating a session to the SGW. and PCO. The SGW transmits a request message (Create Session Request) for creating a session to the PGW-C, and the message for creating a session includes a UE/subscriber identity (IMSI) for PDN connection, APN and PCO are included.

At step 502, the PGW-C supports interworking with 5GS and includes the functionality of SMF. The PGW-C determines whether the PDN connection is subject to interworking if the terminal includes the PDU session ID in the PCO included in the session creation request received in step 501, sends a request to receive 5GS NW slice information for the subscriber and the requested APN to the NF that stored the subscriber information, if the session creation request received in step 501 is for 5GS interworking. transmit. NF is one of UDM, HSS, and UDR, and the service requested by PGW-C is a Slice Selection Subscription Data Retrieval request. The Slice Selection Subscription Data Retrieval request includes the subject subscriber's identifier (SUPI) (using the subscriber ID received in step 501) and additionally carries with it the APN for the current session.

In step 503, the NF that has stored the subscriber information delivers slice information about the subscriber as a response to the PGW-C's request. NF is one of UDM, HSS, and UDR, and the responding service is Slice Selection Subscription Data Retrieval response. The response message contains the subscribed NSSAI (one or more subscribed S-NSSAIs) for the subscriber.

If the subscribed NSSAI for a subscriber includes more than one S-NSSAI, the NF additionally includes in the response message information that can determine the default S-NSSAI for that subscriber. If an APN is included in the request received in step 502, it also includes information used to determine S-NSSAI (single network slice selection assistance information) to apply as a default for the APN. Alternatively, the NF determines the priority of the subscribed S-NSSAIs to the subscriber in the response message, configures information to determine the priority for each S-NSSAI, and responds. Priority either explicitly signals the priority value for each S-NSSAI or includes a list ordered by priority in the response message. It goes without saying that the above examples are not restrictive.

In step 504, the PGW-C provides slice-related information if the Subscribed NSSAI received in step 503 contains two or more S-NSSAIs or more accurate slice selection is required, or Request service from an NF that provides the slice selection function. That is, the PGW-C requests service from an NF such as NSSF (Network Slice Selection Function). Here, it goes without saying that other PGW-Cs can also request services from other NFs that are not NSSFs, without being limited to the above examples.

According to an embodiment of the present invention, the service request message transmitted by the PGW-C (SMF) includes a subscriber identifier (SUBSCRIPTION PERMANENT IDENTIFIER (SUPI) or IMSI), the Subscribed NSSAI received in step 503, and the Contains the received APN (DNN). In addition, the service request message explicitly includes information whether the slice selection or slice information request is a 5G/4G interworking process or a session establishment process considering slices in EPS.

In step 505, the NF, which has received the slice information from the PGW-C (SMF), receives the information contained in the request (subscriber identifier, subscribed NSSAI, APN, etc.), and the current EPS PDN connection will be moved to the future 5GS. Considering that, S-NSSAI is selected.

At step 506, the PGW-C (or SMF or PGW-C, SMF combo node) receives the response message from the NF. NF selects only one S-NSSAI or selects more than one S_NSSAI. If the NF selects two or more S-NSSAIs, it additionally includes information that can determine which S-NSSAI is the default S-NSSAI. Alternatively, if two or more S-NSSAIs are selected, the NF determines the priority of the S-NSSAIs for the subscriber in the response message, configures information to determine the priority for each S-NSSAI, and responds. . Priority either explicitly signals the priority value per S-NSSAI or includes a list ordered by priority in the response message.

At step 507, the PGW-C informs the terminal of the selected S-NSSAI. If the NSSAI of the response message contains only the S-NSSAI of 1, it is notified to the terminal. If the NSSAI in the response message contains two or more S-NSSAIs and the response explicitly specifies the default S-NSSAI, it is preferred. Alternatively, if the NSSAI of the response message includes two or more S-NSSAIs and the priority among the S-NSSAIs can be determined through the response, the S-NSSAI with higher priority is preferentially selected.

The PGW-C notifies the terminal of one selected S-NSSAI, and the S-NSSAI notified to the terminal uses PCO (protocol configuration option) or ePCO. That is, the PGW-C generates a PCO containing at least one S-NSSAI to inform the terminal. If the S-NSSAI that can be notified to the terminal is 2 or more, considering whether the corresponding function of the terminal received in step 501 is supported, if 2 or more S-NSSAI cannot be received, Only one S-NSSAI is selected for transmission. The PCO is included in the Create Session Response message that responds to the SGW and MME.

In step 508, the MME transmits the PCO including the slice information (one or more S-NSSAIs) received from the PGW-C and SGW in the NAS response message to be transmitted to the terminal.

In step 509, the terminal stores the NSSAI received from the MME as information (context) of the PDN connection. The stored NSSAI is used when the UE determines the Requested NSSAI in the registration process when moving to 5GS, or when the PDN connection should be moved to 5GS.

According to an embodiment of the present invention, the NSSAI included in the Registration Request message transmitted by the terminal after moving to 5GS is the union of the NSSAIs received for all generated PDN connections. If two or more S-NSSAIs are stored for the corresponding PDN connection, the terminal applies a method of selecting an S-NSSAI when creating a PDU session in 5GS and sends it to 5GS in a PDU session request message. Transmit including the preserved S-NSSAI. In addition, according to an embodiment of the present invention, only the S-NSSAI that overlaps the S-NSSAI saved for the PDN connection in the Allowed NSSAI included in the Registration Accept message received from the AMF when moving to 5GS. It is included in the PDU session request message and transmitted.

FIG. 6 is a flowchart of a terminal communication method according to an embodiment of the present invention.

In step 601, the terminal sends a PDN connection request message including information on a given APN to the MME. If the terminal supports 5G capability (N1 capability) and the PDN connection requires 5G interworking, the terminal generates and includes a PDU session ID in the PCO or ePCO included in the PDN connection request.

According to one embodiment of the present invention, the process of establishing a PDN connection proceeds with the attach step. Also, the APN in the PDN connection request message is the APN with which the terminal establishes connection.

Also, according to one embodiment of the present invention, the terminal sends information to the MME indicating whether the terminal can receive more than one S-NSSAI via the PCO. Information indicating whether the terminal can receive two or more S-NSSAIs through the PCO is displayed in the capability of the NAS message to be transmitted or in a separate indicator, or as part of the PCO (protocol options etc.).

At step 603, the terminal receives a response message containing at least one network slice information corresponding to the APN from the MME.

According to one embodiment of the present invention, the NAS response message received by the terminal from the MME includes slice information (at least one or more S-NSSAI) received from the PGW (or SGW), and the slice information is the PCO. contained within.

At step 605, the terminal stores at least one network slice information in the response message.

According to an embodiment of the present invention, the terminal stores the NSSAI received from the MME as information (context) of the PDN connection. When the terminal moves from EPS to 5GS, the terminal includes at least one of the stored S-NSSAIs in the PDU session request message transmitted to 5GS.

According to an embodiment of the present invention, when storing a plurality of S-NSSAIs, the terminal transmits any of the plurality of S-NSSAIs through a PDU session request message, Select one and transmit it through a PDU session request message. For example, the terminal includes only the S-NSSAI corresponding to the Allowed NSSAI included in the Registration Accept message among the plurality of stored S-NSSAIs in the PDU session request message and transmits it.

FIG. 7 is a flowchart of a PGW communication method according to an embodiment of the present invention.

In step 701, the PGW receives a PDN connection request message including predetermined APN information from the MME via the SGW. When the PCO or ePCO included in the received request message includes the PDU session ID generated by the terminal, the PGW determines that the PDN connection can be the target of 5G interworking.

According to one embodiment of the present invention, the process of establishing a PDN connection proceeds with the attach step. Also, the APN in the PDN connection request message is the APN with which the terminal establishes connection.

Also, according to one embodiment of the present invention, the PGW receives information indicating whether the terminal is capable of receiving more than one S-NSSAI via the PCO. Information indicating whether the terminal can receive two or more S-NSSAIs through the PCO is displayed in the capability of the NAS message to be transmitted or in a separate indicator, or as part of the PCO (protocol options etc.). Here, it goes without saying that the PGW does not receive information indicating whether the terminal can receive more than one S-NSSAI via the PCO, only the MME can receive it.

In step 703, the PGW requests slice information from the NF, which stores subscriber information, based on the APN information.

According to one embodiment of the invention, the PGW supports interworking with 5GS and includes the functionality of SMF. The PGW sends a request to receive 5GS NW slice information corresponding to the subscriber of the terminal and the requested APN to the NF that stores the subscriber information.

According to an embodiment of the present invention, the NF storing subscriber information is one of UDM, HSS, and UDR, and the service requested by the PGW is a Slice Selection Subscription Data Retrieval request. The Slice Selection Subscription Data Retrieval request includes the target subscriber's identifier (SUPI, using the subscriber ID received in step 501) and additionally carries along the APN for the current session.

At step 705, the PGW receives a response message containing network slice information corresponding to the APN from the NF that stored the subscriber information.

According to one embodiment of the invention, the response message is a Slice Selection Subscription Data Retrieval response. The response message contains a subscribed NSSAI (one or more subscribed S-NSSAIs) for the subscriber.

According to one embodiment of the present invention, if multiple network slice identities (eg, multiple S-NSSAIs) are included in the response message, the PGW selects at least one S-NSSAI and and informs the terminal of at least one S-NSSAI.

For example, if a default S-NSSAI is specified in the response message, the PGW preferentially selects the default S-NSSAI. Also, if the response message contains information about the priority of the S-NSSAI, the PGW selects at least one S-NSSAI based on the information about the priority.

Also, according to an embodiment of the present invention, the PGW requests other NFs to select network slices. For example, NF is NSSF. It goes without saying that the above examples are not restrictive. In FIG. 7, for convenience of explanation, the NF for which the PGW requests network slice selection is described as NSSF, but it is not limited to this.

According to one embodiment of the present invention, the PGW requests the NSSF to select network slice information. The PGW sends to the NSSF a message requesting selection of a network slice including a subscriber identifier (SUPI or IMSI), a Subscribed NSSAI received from an NF that stores subscriber information, and an APN (DNN) received from a terminal. transmit.

Also, according to an embodiment of the present invention, the PGW receives a response message to the network slice selection request. The response message contains information about the network slice selected by the NSSF. Information about network slices selected by the NSSF includes at least one S-NSSAI. That is, the NSSF selects only one S-NSSAI or selects two or more S_NSSAIs. Also, in the response message received from the NSSF, which S-NSSAI is the default S-NSSAI or priority information between S-NSSAIs is included. Priority information is a list.

Also, according to an embodiment of the present invention, the PGW transmits the selected S-NSSAI to the terminal. For example, the PGW identifies whether the S-NSSAI that can be notified to the terminal is two or more, and provides only one S-NSSAI to the terminal or provides multiple S-NSSAIs to the terminal. provide.

In other words, the PGW selects the S-NSSAI directly or requests the NSSF to select the S-NSSAI.

At step 707, the PGW sends network slice information to the MME.

If the response message received from the NSSF contains only one S-NSSAI, it is notified to the terminal. If the NSSAI in the response message contains two or more S-NSSAIs, and the response specifies the default S-NSSAI, the PGW selects the default S-NSSAI in preference, and provides information about the priority among the S-NSSAIs. is included, the S-NSSAI is selected and transmitted based on the information on the priority between the PGWS and the NSSAI.

Here, it goes without saying that the PGW can provide multiple S-NSSAIs to the terminal. If the number of S-NSSAIs that can be notified to the terminal is 2 or more, the PGW transmits one or more S-NSSAIs to the terminal based on information about whether the terminal can receive multiple S-NSSAIs. do.

Also, according to an embodiment of the present invention, the PGW provides an S-NSSAI to notify the terminal using PCO (protocol configuration option) or ePCO.

FIG. 8 is a block diagram showing the configuration of a terminal according to one embodiment of the present invention.

As shown in FIG. 8, the terminal 100 of this embodiment includes a processor 810, a transmitter/receiver 820, and a memory 830. FIG. However, the components of the terminal 100 are not limited to the above examples. For example, terminal 100 may include more or fewer components than those described above. In addition, the processor 810, transceiver 820, and memory 830 can be implemented in one chip.

According to one embodiment, processor 810 controls a sequence of operations of terminal 100 according to the above-described embodiments of the present invention. For example, in a wireless communication system according to an embodiment of the present invention, components of the terminal 100 are controlled to provide services requested by the terminal 100 . There may be a plurality of processors 810, and the processors 810 execute the programs stored in the memory 830 to perform the above-described operations for providing the services of the present invention.

Transceiver 820 transmits and receives signals to and from the base station. A signal transmitted to or received from a base station includes control information and data. The transceiver unit 820 includes an RF transmitter that up-converts and amplifies the frequency of a signal to be transmitted, and an RF receiver that amplifies the received signal with low noise and down-converts the frequency. However, that is only one embodiment of the transceiver 820 and the components of the transceiver 820 are not limited to the RF transmitter and RF receiver. Transceiver 820 also receives a signal through a wireless channel, outputs the received signal to processor 810, and transmits a signal output from processor 830 through the wireless channel.

According to one embodiment, memory 830 stores programs and data necessary for operation of terminal 100 . Also, the memory 830 stores control information or data included in signals transmitted and received by the terminal 100 . The memory 830 may be a recording medium or combination of recording media such as read-only memory (ROM), random access memory (RAM), hard disk, compact disc read-only memory (CD-ROM), and digital versatile disc (DVD). Consists of Also, the memory 830 may be plural, and according to one embodiment, the memory 830 stores programs for controlling components of the terminal to perform the method for inter-system mobility assistance of the present invention. save.

FIG. 9 is a block diagram showing the configuration of NF according to one embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of NF (entity, core network object) in a wireless communication system according to an embodiment of the present invention. Terms such as "... unit" and "... machine" used below mean a unit that processes at least one function or operation, and may be hardware or software, or both hardware and software. is embodied by the combination of According to one embodiment, the NF includes MME, PGW (PGW-C or PGW-U), SGW, UDM, HSS, NSSF, SMF, AMF, etc., and is not limited to the above examples, and is applicable to all core networks. Includes all NFs included. NF in FIG. 9 corresponds to the configuration of the base station.

Referring to FIG. 9, the NF comprises a transmitter/receiver 920, a memory 930, and a processor 910. FIG.

Transceiver 920 provides an interface for communicating with other devices in the network. That is, the transmitting/receiving unit 920 converts a bit string transmitted from the NF to another device into a physical signal, and converts a physical signal received from the other device into a bit string. That is, the transceiver 920 transmits and receives signals. Accordingly, the transceiver unit 920 is called a modem, a transmitter, a receiver, a communication unit, or a communication module. Here, the transmitter/receiver 920 communicates with other devices or systems through a backhaul connection (eg, wired backhaul or wireless backhaul) or other connection method or network.

Memory 930 stores data such as basic programs, applications, and configuration information for NF operations. Memory 930 may comprise volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. The memory 930 then provides the stored data upon request of the processor 910 .

A processor 910 controls the general operation of the NF. For example, processor 910 transmits and receives signals via transceiver 920 . Processor 910 also records data to and reads data from memory 930 . To that end, processor 910 includes at least one processor. Processor 910 controls the NF to perform operations according to the embodiments described above. For example, it controls components of the NF to perform the method for inter-system mobility assistance of the present invention.

The methods according to the claimed or described embodiments of the invention may be implemented in the form of hardware, software, or a combination of hardware and software.

When embodied in software, a computer-readable medium storing one or more programs (software modules) is provided. One or more programs stored on a computer-readable medium are configured for execution by one or more processors in an electronic device. The one or more programs contain instructions that cause the electronic device to perform a method according to the claimed or described embodiments of the invention.

Such programs (software modules, software) may be stored in non-volatile memory including RAM, flash memory, ROM, electrically erasable programmable read-only memory (EEPROM). , magnetic disc storage devices, CD-ROMs, DVDs, or other forms of optical storage devices, magnetic cassettes. Alternatively, it is stored in a memory configured by a combination of some or all of them. Also, each configuration memory may be included in multiples.

In addition, the program can be accessed via a communication network such as the Internet, an intranet, a LAN (Local Area Network), a WLAN (Wireless Local Area Network), or a SAN (Storage Area Network), or a communication network configured by a combination thereof. stored on an attachable storage device accessed via . Such storage devices are connected to devices performing embodiments of the present invention via external ports. A separate storage device on the communication network is also connected to the device implementing embodiments of the present invention.

In the above-described specific embodiments of the present invention, components included in the present invention are expressed singularly or plurally according to the specific embodiments presented. However, the singular or plural terms have been chosen as appropriate to the circumstances presented for convenience of explanation, and the present invention is not limited to the singular or plural components, but rather the plural term. Even elements described in the singular shall consist of the singular, or even elements expressed in the singular shall consist of the plural.

Although specific embodiments have been described as detailed descriptions of the present invention, it goes without saying that various modifications are possible without departing from the scope of the present invention. Accordingly, the scope of the invention is to be defined not only by the described embodiments, but by the appended claims as well as their equivalents and the like. That is, it is obvious to those skilled in the art to which the present invention belongs that other modifications based on the technical idea of the present invention can be implemented. Moreover, each of the above-described embodiments is operated in combination as necessary. For example, a part of the method proposed by the present invention is combined to operate a base station and a terminal. In addition, although the above-described embodiments have been presented based on the 5G system and the NR system, other systems such as the LTE system, the LTE-A system, and the LTE-A-Pro system can also be technically described in the above-described embodiments. Other variations on the idea could be implemented.

100 terminal, HSS, UDM
110 base station (RAN), UDM, HSS
115 PCF, PCRF
120 terminal (UE), SMF, PGW-C
125 UPF, PGW-U
130 SGW
131, 145 Access and Mobility Management Function (AMF) Device 132 Session Management Function (SMF) Device 133 User Plane Function (UPF)
134 Network Slice Selection Function (NSSF) equipment 135 MME
140 data network (DN), E-UTRA base station 150 NR (new radio) base station, NG-RAN
151 AUSF (authentication server function) device 152 NEF (network exposure function)
153 NRF (Network Repository Function)
154 PCF (Policy and Charging Function)
155 UDM (Unified Data Management), terminal (UE)
156 AF (Application Function)
157 SCP (Service Communication Proxy)
158 Terminal 810, 910 Processor 820, 920 Transceiver 830, 930 Memory

Claims (15)

A method of supporting inter-system mobility of a first entity, comprising:
A terminal receives a session creation request message including fields indicating capability information related to APN (Access Point Name) information requesting PDN (Packet Data Network) connection, subscriber identification information of the terminal, and slice identification information of the terminal. stages and
determining whether it is necessary to move to 5GS (5G system) for the PDN connection based on the Create Session Request message;
sending a request for subscriber information including the subscriber identification information and the APN information to a second entity based on the determined result;
receiving from the second entity a response to the request for subscriber information including identification information of one or more subscribed network slices corresponding to the subscriber identification information;
and providing at least one of identification information of said one or more subscribed network slices to said terminal. the capability information related to slice identification information of the terminal includes information indicating whether the terminal is capable of receiving identification information of two or more network slices;
The step of providing at least one of identification information of the one or more subscribed network slices to the terminal includes identifying information of the one or more subscribed network slices based on a field indicating capability information regarding slice identification information of the terminal. 2. The method of claim 1, comprising providing identification information of one or more network slices of identification information to the terminal. 2. The method of claim 1, wherein at least one of the identification information of the one or more subscribed network slices provided to the terminal is included in a predetermined field within a create session response message. The method includes:
sending a message to a third entity requesting selection of a network slice based on identification information of the one or more subscribed network slices;
receiving a response message containing one or more slice identities selected by the third entity from among the identities of the one or more subscribed network slices;
providing at least one of the identification information of the one or more subscribed network slices to the terminal includes transmitting at least one of the selected one or more slice identification information to the terminal; 2. The method of claim 1, comprising: if the response to the request for subscriber information includes identification information of two or more network slices;
2. The method of claim 1, wherein the response to the request for subscriber information includes information for determining a default network slice, or information regarding priority among identification information of the two or more network slices. Method. 2. The method of claim 1, wherein at least one of the identities of the one or more subscribed network slices provided to the terminal is utilized when the terminal moves to 5GS. The first entity is a combo node of EPS (Evolved Packet System) PGW-C (PDN gateway control) and 5GS SMF (Session Management Function),
the second entity is one of Unified Data Management (UDM), Home Subscriber Server (HSS), and Unified Data Repository (UDR);
5. The method of claim 4, wherein the third entity is a Network Slice Selection Function (NSSF). A communication method for a terminal provided with network slice identification information, comprising:
sending a PDN (Packet Data Network) connection request message including information about a predetermined APN (Access Point Name) to a MME (Mobility Management Entity);
receiving a response message including at least one network slice information corresponding to the APN in response to the PDN connection request message;
storing at least one network slice information in said response message;
The method, wherein the at least one piece of network slice information is used when the terminal moves to 5GS (5G system). A first entity that supports inter-system mobility, comprising:
The first entity is
a transceiver;
The terminal receives a session creation request message including fields indicating capability information related to APN (Access Point Name) information requesting PDN connection, subscriber identification information of the terminal, and slice identification information of the terminal, and the session creation request. Based on the message, determine whether a move to 5GS (5G system) is required for the PDN connection, and based on the determination result, subscriber information including the subscriber identification information and the APN information to a second entity, receiving from said second entity a response to said request for subscriber information including identification information of one or more subscribed network slices corresponding to said subscriber identification information; a processor coupled to the transceiver configured to provide to the terminal at least one of identification information of subscribed network slices of the . the capability information related to slice identification information of the terminal includes information indicating whether the terminal is capable of receiving identification information of two or more network slices;
The processor further provides identification information of one or more network slices among the identification information of the one or more subscribed network slices to the terminal based on a field indicating capability information regarding slice identification information of the terminal. 10. The first entity of claim 9, comprising: 10. The first of claim 9, wherein at least one of the identification information of the one or more subscribed network slices provided to the terminal is included in a predetermined field within a Create Session Response message. entity. The processor
sending a message to a third entity requesting selection of a network slice based on identification information of the one or more subscribed network slices;
receiving a response message containing one or more slice identities selected by the third entity from among the identities of the one or more subscribed network slices;
10. The first entity of claim 9, further configured to transmit at least one of the selected one or more slice identities to the terminal. if the response to the request for subscriber information includes identification information of two or more network slices;
10. The method of claim 9, wherein the response to the request for subscriber information includes information for determining a default network slice, or information regarding priority among identification information of the two or more network slices. First entity. The first entity is a combo node of EPS (Evolved Packet System) PGW-C (PDN gateway control) and 5GS SMF (Session Management Function),
the second entity is one of Unified Data Management (UDM), Home Subscriber Server (HSS), and Unified Data Repository (UDR);
13. The first entity of claim 12, wherein the third entity is a Network Slice Selection Function (NSSF). A terminal provided with network slice identification information,
The terminal is
a transceiver;
Sending a PDN (Packet Data Network) connection request message including information about a predetermined APN (Access Point Name) to a MME (Mobility Management Entity), and transmitting at least one packet data network (PDN) connection request message corresponding to the APN as a response to the PDN connection request message. a processor coupled to the transceiver configured to receive a response message including one network slice information and store at least one network slice information in the response message;
The terminal, wherein the at least one piece of network slice information is used when the terminal moves to 5GS (5G system).

Images